Saw bow



A. 0. G. STENMARK AND E. A. HEDBERG.

SAW BOW. APPLICATION FILED m1114921.

1,411,590. Patented-Apr; 4, 1922` @2, wil/4. dWWM/(fry.

PATENT OFFICE.

VQIKEN, SWEDEN', .A CORPORATION 0F SWEDEN.

SAW BOW.

Application led February 10, 1921.

To all wlw/1n t may concern.:

Be it known that we, ANDERS OLoF GEORG STENMARK, a subject of the King of Sweden, and resident of Sandviken, in the Kingdom of Sweden, and ERIK ADoLr Humane., a sub ject of the King of Sweden, and resldent ol' Sandviken, in the Kingdom oit Sweden, have invented certain new and useful Improve,- inents in Saw Bows, of which the following is a specification, reference being had therein to the accompanying drawing.

The present invention relatesto a stretch` ing-device for saw-bows, comprising a lever, pivotally connected with the saw-bow and by means of a link connected with the sawblade, which lever serves to stretch the sawblade.

Accordingto our invention t-he lever 1s arranged centrally in the end of the saw-bow, which for this purpose is slotted. The slot in the saw-bow is of such length, that when the blade is stretched the lever will enter into the slot and will thus be concealed in the end of the saw-bow.

The arrangement is shown in the accompanying drawing where F ig. l shows a saw according to our invention. Figs. 2 and 3 show on a larger scale that end of the sawbow which is provided with the stretchingdevice respectively in side elevation and plan-view. Figs. 4t, 5 and 6 are detail-views.

One end of the saw-blade A is usually attached to one end of the saw-bow B, while the other end of the blade :is attached to the Stretching-device which is provided at the opposite end of the bow. The stretchingdevice comprises a link (l, one end oi which is pivotally connected with the blade A by means of a p-ivot H and the other end ot which is pivotally connected with the shorter arm D of a bell-crank lever D, D1 by means of a pivot F, said lever being pivotally connected with the saw-bow by means of a pivot G. The lever D, D1 is. as shown in Fig. 5, made of a plain piece of sheet-iron and is Supported inside the lower fork-shaped end of the saw-bow. A longitudinal slot K is provided in the outer side of the tubular sawbow intended for the lever arm D1, said arm eing completely entered and hidden in the slot when the lever and the saw-blade are stretched. The arm D1 is provided with an abutment E at its outer, free end, which as shown yin Fig. 5, is formed by a deflected lap Specification of Letters Patent.

Patented Apr. 4, 1922. Serial No. 443,779.

of the sheet, which forms the lever. Said lap abuts against the outside of the sawbow thereby to prevent the arm D1 from entirely entering the tube through the slot K, and to serve as a handle for manually withdrawing the arm from said slot.

lVith our invention the distance between the pivots F and G can be varied without diiculty within very wide limits in order to effect a suitable tension in the saw-blades `for which the bow is intended. The form oit the lever D, D1 also will be simple and easily made and its longer arm D1 in its stretched position is concealed within the handle so as to leave a free pla-ce for the grasp of the hand around the bow.

aving now described our invention, what We claim is new and desire to secure by Letters Patent is:

l. A hack saw, comprising', in combination, a bow formed o1" tubular stock and bifurcated at one end thereof, a bell-crank lever pivoted between the bifurcations of said bow, a saw-blade secured at one end thereof to the end of the bow opposite said bifurcated end, and a link pivotally connecting the opposite end of said blade with one arm of said lever, the bow being provided with a slot at its bifurcated end for receiving the other arm of the lever whereby said arm when in operative position is concealed within the bow.

2. A hack saw, comprising, in combina tion, a bow formed ot tubular stock and bifurcated at one end thereof, a bell-crank lever formed of sheet metal and pivoted between the bifurcations of said bow, a sawblade secured at one end thereof to the end of the bow opposite said bifurcated end, and a link pivotally connecting the opposite end of said blade with one arn'i of said lever, the bow being provided with a slot at its bifur cated end for receiving the other arm of the lever whereby said arm when in operative position is concealed within the bow, said arm being provided with an angular portion forming a stop for preventing the lever from completely entering said slot and forming a handle for manually withdrawing the arm from the slot.

In witness whereof we have hereunto signed .our names.

ANDERS OLOF GEORG STENMARK. ERIK ADOLF HEDBERG. 

